server: add date-modified to datasets

server/src/api/handlers/dataset.rs

@@ -95,21 +95,27 @@ fn _dataset_handler(
             Kind::Date => {
                 let datasets = DateMap::<usize>::_read_dir(&route.file_path, &route.serialization);
 
-                process_datasets(headers, kind, &mut chunk, &mut route, query, datasets)?;
+                process_datasets(&headers, kind, &mut chunk, &mut route, query, datasets)?;
             }
             Kind::Height => {
                 let datasets =
                     HeightMap::<usize>::_read_dir(&route.file_path, &route.serialization);
 
-                process_datasets(headers, kind, &mut chunk, &mut route, query, datasets)?;
+                process_datasets(&headers, kind, &mut chunk, &mut route, query, datasets)?;
             }
             _ => panic!(),
         };
     }
 
+    let (date, response) = headers.check_if_modified_since(&route.file_path).unwrap();
+
+    if let Some(response) = response {
+        return Ok(response);
+    }
+
     let type_name = route.values_type.split("::").last().unwrap();
 
-    let value = match type_name {
+    let mut response = match type_name {
         "u8" => typed_value_to_response::<u8>(kind, &route, chunk)?,
         "u16" => typed_value_to_response::<u16>(kind, &route, chunk)?,
         "u32" => typed_value_to_response::<u32>(kind, &route, chunk)?,
@@ -123,7 +129,10 @@ fn _dataset_handler(
         _ => panic!("Incompatible type: {type_name}"),
     };
 
-    Ok(value)
+    let headers = response.headers_mut();
+    headers.insert_last_modified(date);
+
+    Ok(response)
 }
 
 fn replace_dash_by_underscore(s: &str) -> String {
@@ -131,7 +140,7 @@ fn replace_dash_by_underscore(s: &str) -> String {
 }
 
 fn process_datasets<ChunkId>(
-    headers: HeaderMap,
+    headers: &HeaderMap,
     kind: Kind,
     chunk: &mut Option<Chunk>,
     route: &mut Route,
@@ -159,7 +168,7 @@ where
 
     let path = path.unwrap();
 
-    route.file_path = path.to_str().unwrap().to_string();
+    route.file_path = path.clone();
 
     let offset = match kind {
         Kind::Date => 1,

server/src/api/structs/routes.rs

@@ -1,7 +1,7 @@
 use std::{
     collections::{BTreeMap, HashMap},
     fs,
-    path::Path,
+    path::{Path, PathBuf},
 };
 
 use derive_deref::{Deref, DerefMut};
@@ -15,7 +15,7 @@ use super::Paths;
 #[derive(Clone, Debug)]
 pub struct Route {
     pub url_path: String,
-    pub file_path: String,
+    pub file_path: PathBuf,
     pub values_type: String,
     pub serialization: Serialization,
 }
@@ -52,7 +52,7 @@ impl Routes {
 
             let url_path = split_key.iter().join("-");
 
-            let file_path = key.to_owned();
+            let file_path = PathBuf::from(key.to_owned());
             let values_type = value.to_owned();
 
             if last == "date" {